The 6ES7972-0BA52-0XA0 is a PC Adapter Unit from Siemens. This adapter is designed to be used in conjunction with the Simatic S7-300 PLC product family and serves as an interface between a PC, using the Simatic programmable logic controller, the Siemens software and the PLC. It features a RS232/RS485 interface to connect the PLC and runs on Windows XP, Vista and Windows 7 32/64 bit and Windows 8 32/64 bit operating systems. The 6ES7972-0BA52-0XA0 supports both direct and ISDN (S0) connection types. It also features a 15-pin D-Sub connector for the connection to the PLC, an RS-485/RS-232 port for the connection to the PC and an LED indicator to show the connection status.